2005년 대한 생화학·분자생물학회 하계학술대회를 다녀와서

Recycled powder (RP) is the main by-product in the reclamation of construction and demolition (CD in addition, improvement methods and a benefit evaluation of RP concrete are further introduced. Based on statistical data that describe the activity index of RP and the compressive strength of RP concrete, the median diameter and replacement ratio of RP in concrete preparation should be below 30 μm and 30%, respectively. The use of RP improves the durability of concrete when the RP fineness is superior to the cement fineness. Increasing the RP fineness is an effective approach to improving the properties of RP concrete, and a CO2-curing treatment of RCP is an eco-friendly modification method. Furthermore, the use of RP in concrete has good economic and environmental benefits. Therefore, one expects that this review helps the further use of RP in concrete.

The utilization of eco-friendly recycled powder from concrete and brick waste in new concrete: A critical review

Physical and Functional Characteristics of Foam Concrete: A Review

Building designers' decisions affect long term quality and life cycle cost of buildings. Designers' decisions are usually latent in nature and hard to detect at the early stage of construction. This research looks at failure mechanisms that caused design-related latent defects and the design parameters that could prevent these defects. A 9-month building survey on 74 buildings found that the three most important design-related failure causes were weather impact, impacts from occupants, and loads and moisture from the wet areas. Insufficient considerations for these failures causes were found to be the key in preventing these defects. The design strategies that could successfully prevent triggering these defects include aligning material performance against adverse weather conditions, preventing im- pacts from occupants and loads, preventing water leakage, improving specifications and improving design clarity, details, and layout. There are huge amount of standards and codes available internationally, however, each is designed specifically to overcome regional problems. This research confirms the need for designers to 1 consolidate regional standards and codes; 2 develop in-house database using existing standards and codes, and lesson-learned from defects gathered by property managers; and 3 to apply this knowledge to eliminate latent defects from future design. This research also confirms that such knowledge can be developed using existing records of property managers.

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Latent Building Defects: Causes and Design Strategies to Prevent Them

Use of recycled plastic as fine aggregate in cementitious composites: A review

The rapid urbanization has led to the enormous increase in wastes being disposed of. This paper aims at identifying the possibility of using recycled materials such as crushed glass and plastic wastes in foam concrete as a substitute filler for fine river sand. A protein based foaming agent has been adopted for the study. The workability and strength of different mixes, made using preformed foam, at varying densities using powdered glass and plastic wastes have been investigated. Analysis of foam concrete mixes to identify air-void distribution and its relationship to strength has been done. Effect of superplasticizer inclusion and the corresponding change in the water to solids ratio on compressive strength has also been carried out. The study showed that incorporation of recycled wastes is effective to produce foam concrete of strength that will permit its use for bearing wall applications. Incorporation of PCE based superplasticizer was observed to be effective in enhancing the strength of foam concrete.

Utilization of recycled waste as filler in foam concrete

Accelerated mortarless masonry constructions have been developed or are being used in different countries with limited research studies. This paper discusses first the salient features of interlocking-block masonry and then the development of simple interlocking-concrete-block masonry systems, keeping in view the requirements of shape simplicity and ease of manufacture. Testing of wallettes under axial compression, eccentric compression (e/t ratios of 0, t/6, and t/3), and flexural loading parallel and perpendicular to bed joints were carried out on dry-stacked specimens. Interlocking-block masonry results in relatively high efficiency factors in axial compression and eccentric-to-axial capacity ratio when compared with mortar bedded masonry. Unlike conventional masonry, the flexural capacity of interlocking-block masonry normal to the bed joint is higher than that parallel to the bed joint. A better interlocking mechanism of channel-shaped interlocking blocks, as compared to I-shaped blocks, leads to a relatively higher flexural capacity of the former.

Development and Performance Evaluation of Interlocking-Block Masonry

Influence of superplasticizer family on the durability characteristics of fly ash incorporated cement concrete

High performance concrete especially self compacting concrete (SCC) has got wide popularity in construction industry because of its ability to flow through congested reinforcement without segregation and bleeding. Even though European Federation of National Associations Representing for Concrete (EFNARC) guidelines are available for the mix design of SCC, large number of trials are required for obtaining an SCC mix with the desired engineering properties. The material and time requirement is more to conduct such large number of trials. The main objective of the study presented in this paper is to demonstrate use of regularized least square algorithm (RLS) along with random kitchen sink algorithm (RKS) to effectively predict the fresh and hardened stage properties of SCC. The database for testing and training the algorithm was prepared by conducting tests on 40 SCC mixes. Parametric variation in the SCC mixes were the quantities of fine and coarse aggregates, superplasticizer dosage, its family and water content. Out of 40 test results, 32 results were used for training and 8 set results were used for testing the algorithm. Modelling of both fresh state properties viz., flowing ability (Slump Flow), passing ability (J Ring), segregation resistance (V funnel at 5 min) as well as hardened stage property (compressive strength) of the SCC mix was carried out using RLS and RKS algorithm. Accuracy of the model was checked by comparing the predicted and measured values. The model could accurately predict the properties of the SCC within the experimental domain.

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Modeling the Fresh and Hardened Stage Properties of Self-Compacting Concrete using Random Kitchen Sink Algorithm

Masonry construction over the last century has undergone radical changes that have led to specific improvements in construction performance due to the advent of large-sized blocks, innovative metho...

K. B. Anand

Papers

Utilization of recycled waste as filler in foam concrete

Development and Performance Evaluation of Interlocking-Block Masonry

Influence of superplasticizer family on the durability characteristics of fly ash incorporated cement concrete

Modeling the Fresh and Hardened Stage Properties of Self-Compacting Concrete using Random Kitchen Sink Algorithm

Laboratory-Based Productivity Study on Alternative Masonry Systems